Convention, in diplomacy, a treaty not definite and permanent, but having some special and temporary purpose; in politics, an assembly of a special and peculiar character. According to the British constitution, no parliament can be convened by any other authority than that of the sovereign, nor can a change of dynasty form the subject of its deliberations. Accordingly, in 1660, a convention was held in London to restore Charles II. to the throne, and its acts were afterward ratified by parliament. At the revolution of 1688 the prince of Orange summoned the lords and commons to meet in convention. That body settled the succession upon William and Mary, and was afterward declared to be the two houses of parliament. There was a convention of the estates of Scotland in March, 1689, to settle the Scottish crown upon William and Mary, which was changed into a parliament on the 5th of June. The annual meetings of the commissioners of the royal burghs of Scotland are also called conventions. In America the same term was applied to those bodies which at the commencement of the revolution assumed the powers previously exercised by the colonial governments, and especially to those by which the state and national constitutions were framed. - In French history the sovereign assembly which convened after the insurrection of Aug. 10, 1792, and the imprisonment of Louis XVI., is known as the convention.
This body was organized Sept. 21, 1792, and immediately abolished royalty and proclaimed the republic. It brought the king to trial Dec. 11; condemned him to death by a majority of 26 out of 721 votes, Jan. 16, 1793; established the revolutionary tribunal, March 10; decreed the formation of the committee of public safety, April 6; allowed the arrest of 21 Girondists, June 2; completed a new constitution, Aug. 10; decreed a universal levy for the national defence, Aug. 23; condemned Marie Antoinette, Oct. 16; appointed a committee with Sieyes at its head to frame a second constitution, April 19,1794; received and adopted this constitution, June 23; ordered the arrest of Robespierre, July 27; prohibited the affiliation of clubs, Oct. 16; suppressed the Jacobins, Nov. 12; was successfully defended by Bonaparte against the sections of Paris, Oct. 5, 1795; decreed the abolition of capital punishment, handed over the government to the directory and the council of 500, and finally adjourned, Oct. 26, after having been in session three years and 35 days, and passed 8,370 decrees. - At present the term convention is applied in the United States not only to delegated bodies specially assembled by legislative authority, but to voluntary assemblies of delegates having some change of legislation or policy in view.
It is also applied to bodies assembled as the representatives of parties, to make nominations to office or settle principles of action. The great quadrennial conventions of the respective parties have since 1836 played a very important part in politics; for though they have no legal or constitutional sanction, they nominate the president and vice president, and by their platforms or declarations of principles determine the policy of the country for the next four years. Their meetings are attended by great crowds, and their proceedings, which generally take two or three days, are watched with universal interest throughout the country. (See Constitutional Convention).